Copper in Maryland Drinking Water — 16 ZIPs Tested
EPA data analysis for copper in Maryland drinking water systems
Copper Contamination in Maryland
ZipCheckup analyzed drinking water data across 615 ZIP codes in Maryland for copper contamination. 16 ZIP codes have reported copper detections, and 15 have EPA violations on record.
The violation rate for copper in Maryland is 2.4% of all ZIP codes — roughly in line with the national average.
EPA Standard for Copper
The EPA maximum contaminant level (MCL) for copper is 1.3 mg/L (action level), governed by the Lead and Copper Rule. Water systems that exceed this limit must take corrective action and notify consumers.
Worst ZIP Codes for Copper in Maryland
These ZIP codes reported the highest copper levels in Maryland based on CCR reports and EPA data:
Lowest Copper Levels in Maryland
These ZIP codes had the lowest reported copper detections in Maryland:
Health Effects of Copper
Short-term exposure to copper above the action level causes gastrointestinal distress (nausea, vomiting, diarrhea). Long-term exposure can cause liver and kidney damage. People with Wilson's disease are particularly sensitive.
How to Remove Copper From Drinking Water
The most effective treatment for copper removal is Reverse Osmosis or NSF 53 Carbon Block. Look for filters certified under NSF 53 standards.
Check Your ZIP Code
Use the ZipCheckup water quality search to see copper data for your specific water system in Maryland.
Worst ZIP Codes for Copper in Maryland
Ranked by highest copper detection level.
| Rank | ZIP Code | City | Level Detected | EPA Limit | Status |
|---|---|---|---|---|---|
| 1 | 21917 | Colora | 4950 ppb | 1300 ppb | Exceeds |
| 2 | 21660 | Ridgely | 1900 ppb | 1300 ppb | Exceeds |
| 3 | 21682 | Ridgely | 1900 ppb | 1300 ppb | Exceeds |
| 4 | 21683 | Ridgely | 1900 ppb | 1300 ppb | Exceeds |
| 5 | 21688 | Ridgely | 1900 ppb | 1300 ppb | Exceeds |
| 6 | 21041 | Ellicott City | 1780 ppb | 1300 ppb | Exceeds |
| 7 | 21042 | Ellicott City | 1780 ppb | 1300 ppb | Exceeds |
| 8 | 21043 | Ellicott City | 1780 ppb | 1300 ppb | Exceeds |
| 9 | 21048 | Finksburg | 1700 ppb | 1300 ppb | Exceeds |
| 10 | 21153 | Stevenson | 1690 ppb | 1300 ppb | Exceeds |
| 11 | 21154 | Street | 1600 ppb | 1300 ppb | Exceeds |
| 12 | 21645 | Kennedyville | 1420 ppb | 1300 ppb | Exceeds |
| 13 | 20854 | Potomac | 1400 ppb | 1300 ppb | Exceeds |
| 14 | 20859 | Potomac | 1400 ppb | 1300 ppb | Exceeds |
| 15 | 20754 | Dunkirk | 1390 ppb | 1300 ppb | Exceeds |
| 16 | 21719 | Cascade | 1.25 ppm | 1.3 ppm | Within Limit |
Lowest Copper Levels in Maryland
Cities with Copper Data in Maryland
5 cities in Maryland have copper testing data available.